Abrading tool



March 2, 1937. w. R. BARCLAY ABRAD I NC: TOOL Filed Dec. 4, 1954 Fig".2.

Patented Mar. 2, 1937 UNITED STATES PATENT OFFICE ABRADING TOOL WilliamRoderick Barclay, Leicester, England,

assignor to United Shoe Machinery Corporation, Paterson, N. J., acorporation of New Jersey Application December 4, 1934, Serial No.755,972 In Great Britain June 5, 1934 Claims. (O1. 51194) This inventionrelates to abrading tools and is pad for supporting an abrasive coverupon the herein disclosed as embodied in a disk type of above-mentionedtool; tool such as is used in buffing the shank and heel Fig. 3 is asectional view taken on the line breasts of shoes. In the applicationfor United IIIIII of Fig. 2;

5 States Letters Patent of Fred Ricks and Ernest Fig. 4 is a sectionalview taken on the line 5 Hope, Serial No. 755,962., filed December 4,1934, IV-IV of Fig. 2; there is disclosed a disk type of tool whereinthe Fig. 5 is a perspective view of the abrasive eleabrasive element issupported upon an inflatable ment used on the tool; and

ring. The abrasive element of that tool consists Fig. 6 is a viewshowing a joint in the abrasive 10 of a strip of abrasive sheet materialmolded to element. 10 conform to the periphery of the supporting ring.Referring to Fig. 1, the illustrated tool is shown The ends of theabrasive strip are adhesively in operation upon the breast surface of aheel H secured together in overlapping relation, and the of a shoe S. Asillustrated, the tool is supported expansion of the ring by air pressureholds the upon the tapered end of a tubular spindle I!) which abrasiveelement in place. The tool disclosed in is driven by a y Suitable meansetool com- 5 the present application is similar in the respects, prises abody portion in the form of a wheel l2 above mentioned to the tooldisclosed in the which is conveniently made of aluminum and applicationof Ri k nd H which has a hub H1 in which is formed a socket It is anobject of the present invention to profor receiving the end of the p d ell- The tool vide an improved abrading tool of the character body 12 isof general discoidal form but its cen- 2 under consideration. Inaccordance with a featral portion is s w COnVeX toward the p ture of theinvention, the expansible ring is redle l0. Slidably fitted over the hubI4 is a hub cessed at the lapped joint of the abrasive element of a a pm mb "5 of substanti lly the to avoid undue bulkiness at this locality.In the same diameter as the tool body l2. The periphillustrated tool theouter wall of the expansible ry of he to l bo y I is rec ed nd thetoclring is of substantially the same thickness at the body I2 and theclamping member I6 have flanges recess as at the other portions of thering in a a respectively, formed t ereon- A nut order to prevent bulgingof the ring at this locality 22 is threaded upon the hub 14 in abuttingre awhen expanded by air pressure. In accordance tion to the hub of theclamping member I6.

with a further feature, the expansible ring has Mounted upon th p p y ofthe tool dy 30 a gritty surface to prevent slip between the abra- I2 isan t b e ring 24 of rubbers ring sive element and the ring in order toinsure that is shown in perspectiv in and the form the'lapped joint ofthe abrasive element will alof its radial section is shown in Fig- Atthe ways be in register with the recess in the exbase of the ring thereextends inwardly a tongue pansible ring. The gritty surface of the ringis 26 by w h t ring is clamped between t d sk 35 obtained byincorporating particles of frictiona d t e 13 0 dy The p e I has anproducing material, for example flint, in the peaxial passageway 23which, a its pp d, is ripheral surface portion of the ring prior totreat- Connected With a y Suitable Source of a under ment of the ring ina vulcanizing mold. The pressure. A small tube 30 opens at one end intoincreased frictional characteristics of the ring rethe Socket 0f the endat its other end 40 sulting from such treatment are umcient to tends theSurface of the recessed overcome any tendency of the abrasive elementperlnherel portlPn of t tool body wh to creep which might otherwiseresult from the the inflatable ring 24 is assembled in positionfrictional drag of the work upon the abrasive upon the tool Smallopentng through: the

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w the afbove i other oblects featmjes The ring 24 is provided with anannular air chamin view, the 1nvent1on will now be described with her 32which communicates with the above ref erence the accPmpanymg drawmg andmentioned opening in the tongue 25. Air under pomted out m Clalms'pressure will thus pass from the passageway 28 5 In the drawmg, 0 intothe socket of the hub l4, thence through the Fig. 1 is an e1evat1onalview, partly in section, tube 30 and t pening in the tongue 25 into ofthe improved tool in operation upon the breast th air h b 32 t inflateth i 24 As surface o the S e e is shown in Fig. 4, the wall of the airchamber 65 2 is a View in PerspectiVe f ab e 2 is thinner at theperipheral portion of the ring than at its sides, in order that the airunder pressure being introduced into the ring will cause the expansionof the ring to take place diametrically rather than transversely. Thering 24 may conveniently be made by vulcanizing together two suitablepieces of rubber in a mold, and as shown in Figs. 3 and 4, a strip 34 ofcanvas may be introduced at the joint at the base to strengthen thering.

As shown in Figs. 1, 5 and 6, the abrasive element of the tool consistsof an annular cover 36 of abrasive sheet material. The abrasive cover 36has an inherent shape which is similar to that of the periphery of thering 24. This shape may conveniently be obtained by a molding operationwhich is illustrated and described in the abovementioned application ofRicks and Hope. The cover is applied to the tool when the ring 24 is indeflated condition, an overlapping end of the cover being cemented to anunderlapping end.

As so far described, the abrading tool, including the abrasive cover 36is similar to the tool disclosed in the above-mentioned application ofRicks and Hope. In the present construction, however, the tongue 26 isnot of dove-tail formation but is provided with annular recesses 38, 38at its base to accommodate the flanges l8 and 20 of the tool body andclamping disk, respectively. As shown in Fig. 6, the overlapping end 3!of the abrasive cover 36 in forming the joint is of a re-entrantV-shaped outline so that the joint is of greater extent at the sidesthan at the center of the cover. In the ordinary use of tools of thischaracter, the side surfaces of the abrasive cover are used more thanthe central portion and this form of joint gives added strength at thelocalities where strength is most required, without rendering the jointunduly bulky. The abrasive material need not be removed from the endportions of the cover 36 at the point and is preferably retained atleast upon the overlapping end.

The surface portion of the ring 24 which underlies the abrasive coverhas incorporated in it particles of grit to increase its frictionalcharacteristics. This is accomplished by sprinkling minute particles ofgrit, for example flint, upon the surface of the ring prior to thetreatment of the ring in a vulcanizing mold.

As shown in Fig. 2- the inflatable ring 24 has a recessed portion 40 inits peripheral surface. Fig. 3 represents a cross section of the ringtaken through this recessed portion. The recessed portion is of a lengthsomewhat in excess of the length of that joint of the abrasive cover.The depth of the recess is substantially equal to or slightly in excessof the thickness of the abrasive sheet material from which the coversare made, and the recess at each end terminates in a shoulder 42 whichconveniently is not perpendicular to the adjacent surface but isinclined at an angle of about In order to prevent the absence ofmaterial at the recessed portion 40 from causing undue inflation of thering at that locality, the ring is so formed that the annular airchamber 32 at the recessed portion is displaced inwardly toward thecenter of the ring a distance corresponding to the depth of the recess.Thus, as appears from the comparison of Figs. 3 and 4, the same amountof material is left between the peripheral surface of the ring and theannular air chamber, both at the recessed portion 43 and at theremaining portions of the ring, and uneven inflation is therebyprevented.

The abrasive cover 36 is applied upon the ring 24 when the latter is indeflated condition. The ends of the abrasive cover are cemented togetherin overlapping relation at the locality of the recess 40. the hollow 32,the expansion of the ring will hold the abrasive cover in place, and thegritty surface of the ring will prevent any tendency on the part of theabrasive cover to creep in such a manner as to move the joint away fromthe recess 40. The recess 40 insures an even surface of the abrasivecover notwithstanding the joint.

Having described the invention, what is claimed as new and desired to besecured by Letters Patent of the United States is:

1. An abrading tool comprising a supporting member and a cover ofabrasive sheetmaterial mounted upon said supporting member, saidabrasive cover having its ends adhesively secured together to form alapped joint, and said supporting member being recessed at the localityof. the joint to prevent undue bulkiness at that locality.

2. An abrading tool comprising an expansible pad, and an annularabrasive cover carried by said pad and retained upon said pad by theexpansive pressure of the latter, said abrasive cover having a lappedjoint, and said pad having a recess to accommodate said lapped joint.

3. An abrading tool comprising an inflatable pad adapted to carry anabrasive cover and having a recess in its cover-supporting surface toaccommodate a lapped joint in the abrasive cover.

4. An abrading tool comprising an inflatable pad having an outer surfaceadapted to carry an abrasive cover and having a recess in its outersurface to accommodate a lapped joint in the abrasive cover, the outerwall of said pad being of substantially the same thickness at saidrecess as at other portions of said pad.

5. An abrading tool comprising an annular inflatable pad, and an annularabrasive cover carried by said pad and retained upon said pad by theexpansive pressure of the pad when the latter is inflated, said abrasivecover having a lapped joint, and said pad having a recess to accommodatesaid lapped joint, said pad having also particles of gritty materialincorporated in its cover-supporting surface to prevent relative slipbetween the pad and the cover and thereby to When air pressure isadmitted into keep the lapped joint in register with the recess.

WILLIAM RODERICK BARCLAY.

